Endless track for vehicles



March 6, 1945.

P. H. JOHNSON ENDLESS TRACK FOR VEHICLES Filed July 23, 1941 3 Sheets-Sheet l March 6, 1945. p. JOHNSON 2,370,667

ENDLESS TRACK FOR VEHICLE S Filed July 23, 1941 3 Sheets-Sheet 2 y 2 flm, flaw 77 l I V f J 151 I .HPIIIIIILI I I I ll 3 Sheets-Sheet 3 1--- llL n.

llllllll-lll P.'H. JOHNSON ENDLESS TRACK FOR VEHICLES Filed July 25, 1941 March 6, 1945.

Patented Mar. 6, 1945 ENDLESS TRACK FOR VEHICLES Philip Henry Johnson, Hounslow, England, as-

signor to Roadless Traction Limited, Hounslow,

Middlesex, England i Application July 23, 1941, Serial No. 403.751 y In Great BritainyMay '7, 1940 8 Claims.

This invention relates to endless tracks of the locked girder type; that is to say those in which the links interlock with one another to form a rigid girder, the abutments being so formed that the track is laid upon the ground to a predetere mined arc.

It is already known to construct track links from sheet metal, the side members having lugs and abutments for the interlock being formed by bending up the end portions of the sheet, leaving the intermediate portion to constitute the ground plate.

In practice, for smaller sizes the design of the link lends itself to pressings in comparatively thin material, but as regardsthe larger sizes a heavy steel casting is needed.

Difiiculties have thus arisen due to the fact that it is impracticable to press the links out of sheet steel of more than a certain thickness, and equallyimpracticable to make these links of steel castings of less than a certain size. The intermediate sizes have therefore proved troublesome. For instance it is practicable to make links from pressings for endless track units of ,weight carrying capacity of 10 cwt., but for units employing steel castings for the track link it is not generally practicable to provide the units of less carrying capacity than about tons.

The object of the present invention is to provide a type of link of the kind in question which can be used for any size of unit, having greater load carrying capacity than those which are produced from pressings; and not requiring the employment of steel castings.

According to the invention the ground plate, the side members and the roller pathmembers are separate elements so constructed and arranged for mutual assembly that when secured together as by welding, a product is obtained which is satisfactory for all sizes of unit. The type of construction also provides for a considerable eheapening of the product whilst the design offers the prospect of appreciably increased life and lends itself to an accuracy ofconstruction not readily obtainable when the unit is a steel casting or even a pressing.

Preferably the elements of which the unit is fabricated are made by cutting sheet metal to the' fened by longitudinal and transverse ribbing disposed between the member and the ground plate and welded to these parts respectively,

The upper portions of the side members are adapted to serve as a guide to the weight carrying rollers of the complete track unit which bear on the roller path members.

The ground plate preferably extends on either side of the side members to give additional bearing surface on the ground and these extensions of the ground plate may be turned up to an angle or rounded so as to facilitate steering. The extensions of the ground plate may also be ribbed down from the side members t give additional strength,

Itit is desired to have a larger bearing surface between the lugs of the interlocking side 'members and the abutments formed by the roller path members than is provided by the width of plate employed for the manufactureof the side members, there may be welded on to the side members attheir lug portions additional suitable pieces of slots in the side members, thus relieving stress on the welding and providing in a simple way for the abutments required to interlockwith the lugs which form part of the side members. The roller path memberlocated above the level of the hinge pins, will be appropriately supported and stifplate. These pieces of plate would preferably be carriedback as far as the hinge pins,,and so both the wearable interlocking faces of the side members and the wearable bearing for the hinge pin may be considerably increased without adding much to weight.

As an alternative to the foregoing and with the same object in view, 1. e., the provision of additional area to the interlocking abutments and the hinge pin bearings, the construction can be so arranged that the upper portion of the side member is duplicated alongside, the two being connected in such a way as to give the additional bearing surface required. In the case of the abutments, the'ccnnection would be formed by a suitable piece of horizontal plate and in the case of the hinge pin, by apiece of tubing, all parts being securely weldedtogether. Thus in efiect, without great increases in weight, there is obtained a side member having wearable surfaces corresponding with what would be given by aside member originally formed of excessively thick plate.

In the event of it being desired to minimize the noise created by' the track links when they come into interlocking position round the end rollers of the complete track unit, small blocks of rubber can be provided between parts which move relatively to one another when the track lines pass from the unlocked position to the locked position and vice versa. Moreover to give increased life to parts coming into metallic contact, the surfaces. involved may be appropriately heat-treated or case-hardened in order to ensure a high Brinell figure.

When in course of time the surfaces where metallic contact takes place become worn, the construction lends itself to ready repair. Over size hinge pins, for instance, can be fitted, the

holes to receive these being bored out to suit. When the interlocking surfaces have worn so'that the girder is fiat and no longer has the desired curvature, the surface can be built up again by welding preferably with electrodes which give a high 'Brinell figure.

In the accompanying drawings,

Figures 1 and 2 are diagrammatic perspective views of an internal and external link designated A and B.

Figure 3 is a side view on a smallerscale of links A and B in the locked position and a third link A in the displaced position.

Figures 4'and 5 are plan views respectively of the links A and B of Figure 3.

Figure-6 and '7 show in plan and side view a modified construction in which an additional area is provided for the interlocking abutments and hinge pin bearings.

Figures 8 and 9 show in plan and side view a modified form of link.

In the constructions illustrated, the main parts are the ground plate 1, the side plates 2 and the roller path members 3. The roller path members 3 are provided with tongues 5 projecting through slots 6 inthe side plates 2 and these tongues are welded to the side plates 2 at l. The tongues 5 constitute the abutments required to interlock with the lug l partly formed by the side plates 2 and partly by pieces 1 welded on to the side plates.

The roller path members 3 are located above the level of the hinge pins and are supported and stifiened by longitudinal and transverse ribbing I0, I I respectively placed between the roller path member 3 and ground plate I and'welded to these parts as at I2, l3 and to the side plates 2. Both the side plates 2 and the transverse ribbing H are bored at 9 to accommodate the hinge pins. The upper portions M of the side plates 2 which are reinforced with blocks i4 welded thereto, serve as guides for the weight carrying rollers which bear on the roller path members 3.

The ground plates l'extend beyond the side members 2 as at l5, thus constituting an additional bearing surface and they are also turned or rounded up at Hi to facilitate steering.

If desired a larger bearing surface between the lugs l of the side members 2 and the abutments formed by tongues 5 of the roller path members 3 can be provided for by welding on to the bottom plates l additional pieces of plate 11 (see Figures 6 and 7), an extension of the bearing for the hinge pin being formed of tubing l8; all parts being welded together so constituting a larger bearing surface. To minimize noise created by the track links small blocks of rubber l9 may be provided carried by the transverse ribbing H of external links B. The rubber blocks l9 contact with the under-side'of the roller path 3 of internal link A to cushion the blow created by the track links when they come into interlocking engagement.

To cover the gap between adjacent links when displaced, a piece 28 is welded to the ground plate which overlaps the ground plate of an adjacent link. v

In the modification illustrated in Figures 8 and j 9, the side members are not welded together, one

of them being brought towards the outer edge of the ground plate. This re-arrangem-ent has the notable advantage of stiffening up that portion of the roller path which extends outwardly to form one of the interlock abutments.

What I claim is 1. An endless track. of the locked girder type having links fabricated from separately made ground plates, side members and roller path members assembled and secured together, the roller path members having tongues projecting through slots in side members.

2. An endless track as claimed in claim 1 in which metal pieces are secured to the side members so that there is provided a larger bearing surface between side members and the tongues of roller path members than is provided by the thickness of side members.

3. An endless track as claimed in claim 1 in which additional bearing surface between interlocking side members and abutments formed by roller path members is provided by securing on to the bottom plates additional pieces upstanding parallel to the side member and connected to the latter.

4. An endless track as claimed in claim 1 in which additional bearing surface between interlocking side members and ab-utments formed by roller path members is provided by securing on tubing providing additional bearing for the hinge pins.

5. An endless track of the locked girder type having links fabricated from separately made ground plates, side members and roller path members assembled and secured together, pieces being secured to ground plates to overlap the ground plates of adjacent links and so cover the gaps between links when displaced.

6. An endless track of the locked girder type having links fabricated from separately made ground plates, side members and roller path members assembled and secured together, resilient material being incorporated so as to be interposed between portions of adjacent links which move relatively to one another when the links pass from the unlocked position to the locked position.

7. An endless track of the locked girder type having links, fabricated from separately made ground plates, side members and roller path members assembled and secured together, the roller path members being located above the. level of the openings in the side members for the link hinge pins and being supported and stiffened by ribbing disposed between the members and the ground plates and secured to these parts respectively, and a block of resilient material being carried by the ribbing under a roller path member so as to contact the underside of the roller path member of an adjacent link and so cushion the blow when the links come into inter-.

locking engagement.

8. An endless track of the locked girder type having links, fabricated from separately made ground plates, side members and roller path members assembled and welded together, the 

